'Paranormal Activity 3' Teaser: Tweet to See the Film in Your Town First (Moviefone Exclusive)

2011 may be light on horror films, but that's all about to change with the coming release of 'Paranormal Activity 3.' The third film in the nearly $400 million-grossing phenomenon arrives in theaters on Oct. 21, and -- judging from this new 30-second teaser -- you can expect the film to scare the pants off you and yours through Halloween and beyond. VHS tapes! Invisible demons! Creepy little girls! Watch ahead.

'Paranormal Activity 3' arrives in theaters on Oct. 21, though if you want to see a special sneak preview of the film in your own city on Oct. 18, head to Twitter. Through the "Tweet to See It First" campaign, Paramount will debut the film in the top 20 cities with the most tweets, three days before release.

Voting happens at www.ParanormalMovie.com, where fans can select their cities and tweet with a specially marked hashtag. The campaign ends on Thursday, Oct. 13, with winners announced on Friday, Oct. 14. Get tweeting!